• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.43 no.10
• /
• pp.888-895
• /
• 2015

This paper shows an approximate equation which calculates a flapping angle of blade for verification of KUH safety area. The flapping behavior of blade must be reviewed in an aspect of safety because of a collision possibility with airframe. However, it is difficult to measure an exact flapping angle during flight. A prediction equation of a coning angle is derived from aeromechanics and that of a dynamic flapping angle is derived from analysis results in development phase, respectively. Following, the equations are verified by comparison the flapping angle through an aircraft simulation test to a calculation. Finally, the safety area, which was established in development phase, is verified by calculating a flapping angle during the flight which is required by the terms of safety based on AC29 and FAR29.

• Journal of Korean Society of Forest Science
• /
• v.90 no.1
• /
• pp.139-145
• /
• 2001

Behavior of Matsucoccus thunbergianae Miller and Park males immediately after emergence from their cocooning site, and meteorological factors affecting the responsiveness of the flying males to synthetic pheromone were studied. On Pinus thunbergii saplings, newly emerged males walked around to locate females. The males lanuched themselves into flight after up to three times of copulation. Without the presence of females, the males took off within five minutes whereas when the females were placed nearby but copulation was artifically prohibited the males did not take off. In a wind tunnel, the presence of female pheromone discouraged male take off. More males were flying in sunny area than in shade, but light intensity had no effect on the responsiveness of males toward the pheromone source. Wind speed was the main meteorological factor that affected the male responsiveness. Most males, after hitting the substrate near pheromone source with various posture, stood on their feet and approached the source.

• Journal of Advanced Navigation Technology
• /
• v.25 no.5
• /
• pp.327-335
• /
• 2021

Navigational Aids Facilities help aircraft navigate by using wired communication, wireless communication, satellite, light, color and radio waves. Navigational Aids Facilities are used in all processes of aircraft operation, and if there is a problem with the facility, it may lead to delays in flight operation, cancellation of flights, and major airline accidents, resulting in enormous loss of life and property. In the management and operation of Navigational Aids Facilities, various outcomes will be brought about according to the advancement with the safety culture. The purpose of this study is to investigate the effect of advancement on safety culture in the operation of Navigational Aids facilities not only on members and customers, but also on benefits to bring to whole society. In this paper, the analysis results are presented using the structural equation model, and the meaning is presented in the conclusion.

• Geomechanics and Engineering
• /
• v.31 no.6
• /
• pp.573-582
• /
• 2022

The geometry of the gravity-type anchorage changes depends on various factors such as the installation location, ground type, and relationship with the upper structure. In particular, the anchorage geometry embedded in the ground is an important design factor because it affects the pull-out resistance of the anchorage. This study examined the effect of four parameters, related to anchorage geometry and embedded ground conditions, on the pull-out resistance in the gravity-type anchorage through two-dimensional finite element analysis, and presented a guide for major design variables. The four parameters include the 1) flight length of the stepped anchorage (m), 2) flight height of the stepped anchorage (n), 3) the anchorage heel height (b), and 4) the thickness of the soil (e). It was found that as the values of m increased and the values of n decreased, the pull-out resistance of the gravity-type anchorage increased. This trend is related to the size of the contact surface between the anchorage and the rock, and it was confirmed that the value of n, which has the largest change rate of the contact surface between the anchorage and the rock, has the greatest effect on the pull-out resistance of the anchorage. Additionally, the most effective design was achieved when the ratio of the step to the bottom of the anchorage (m) was greater than 0.7, and m was found to be an important factor in the pull-out resistance behavior of the anchorage.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2006.03a
• /
• pp.784-793
• /
• 2006

As the number of CFRD constructions increases, the necessity of an accurate assessment on its behavior also has been increasing accordingly. The performance of concrete faced rockfill dam (CFRD) under different water levels is greatly concerned by dam engineers and designers in the world. However, domestic research on CFRD design and construction has yet been insignificant. This study deals with three centrifuge model tests, mainly investigates the deformation of the concrete faced slabs with different face slab stiffness under different water levels. The prototype of a centrifugal model dam is half size of domestic CFRD dam. Detailed material preparation, model design, model set-up, model instrumentation and testing procedures are presented. In order to simulate the prototype concrete faced slab, three kinds of thin fiberglass plates with different thickness was adopted in the three model tests. The water level control facility was specially designed for this experiment to control the water level rise and drawdown during centrifuge flight. Although most of the results from the three model tests are satisfactory, it is also required that the centrifuge test results should be compared with those of numerical analysis and field measurements to analyze the centrifuge test results more in detail.

• Journal of Convergence for Information Technology
• /
• v.9 no.4
• /
• pp.68-77
• /
• 2019

The purpose of this study is to identify the optimal model to explain safety behavioral intention according to the recognition of safety communication in cabin through comparison of Planned behavioral theory and Triandis' theory of interpersonal behavior. In order to accomplish the study purpose, research model and hypothesis were established based on the previous research. As a result of the analysis, it was found that attitude and Perceived Behavioral Control had a positive effect on the safety behavioral intention. Triandis theory shows that social factors and habits have a positive impact on safety behavioral intention. In addition, A comparison of the two models confirms that both psychological processes of recognition and emotion are accompanied by the relationship between safety information awareness and safety behavioral intention.

• Journal of Convergence for Information Technology
• /
• v.7 no.6
• /
• pp.35-43
• /
• 2017

The purpose of this study was to analyze the converged influencing factors on the stages of exercise behavior changes in shift work nurses. The subjects were 120 shift work nurses working in hospitals who understood the purpose of the study and agreed to participate in the study. Data were analyzed using frequency, percentage, mean, standard deviation, t-test, $X^2$ test, and multiple logistic regression analysis. The exercise motivation factors of shift work nurses had a significant effect on stages of exercise behavior change (${\beta}=2.480$, p=.022), health status perceptions(${\beta}=1.151$, p=.013). Social support factors (${\beta}=1.819$, p=.002) and marital status (${\beta}=-1.820$, p=.004) also had significant effects on the stages of exercise behavior change of shift work nurses. In other words, subjects with change in exercise behavior had 11.9 times higher motivation and 3.1 times higher health status perception than those without change in exercise behavior, social support was 6.1 times higher, and unmarried subjects showed 16 times showed higher than that of married subjects. Therefore, it is important to develop a strategy to practice continuous and regular exercise in consideration of the exercise motivation, social support, and health status perception of the nurses in shift work.

• Journal of Korea Game Society
• /
• v.12 no.6
• /
• pp.33-46
• /
• 2012

This research aimed to analyze the way of how flying movement system and background graphic in MMORPG, which provides movement system, influences on users' psychological behavior in order to enhance user's participation and the completion level of 3D game. This research also analyzed the difference between the user's response to the flying movement and other movement structure in game such as things to board, summons, portal, chase, and etc. With this comparative analysis, this study could clarify the characteristics of the user's desire to fly according to the virtual world' topography in game, the necessity of flying movement for fast movement, the dependence of user on flying system, the immersion according to behavior in process of flying, and expression level of virtual world, and etc. The survey through the case research of MMORPG Aion selected for this research showed flying movement system can have suitable quality by applying users' playing time and absorption in flight process, users' impulse following game level, and users' need to fly as a convenience of flying properly.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2007.05a
• /
• pp.160-164
• /
• 2007

In the steel industry, there is a need to produce large forged parts for the automobile industries, the flight and shipping industries ad military industries. In the steel-industry application, a cogging technique for cast ingots is required, because the major parts are needed as one large body in order to obtain higher quality. Therefore, cogging process is the primary step in manufacturing of practically large open-die forging. In the cogging process, internal voids have to be eliminated as defects, The present work is concerned with the elimination of the internal voids in large ingots so as obtain sound products. In this study, hot compression tests were carried out to obtain the flow stress of cast microstructure at different temperature and strain rates. The FEM analysis are performed to investigate the overlap defect of cast ingots during cogging stage. The measure flow stress data were used to simulate the cogging process of cast ingot using the practical material properties. Also the analysis of void closure are performed by using the $DEFORM^{TM}$-3D. The calculated results of void closure behavior are compared with the measured results before and after cogging, which are scanned by the X-ray scanner. From this result, the criteria for deformation amounts effect on the void closure can be investigated by the comparison of practical experiment and numerical analysis.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.6
• /
• pp.780-786
• /
• 2005

This study presents a non-video, non-invasive, automatic, on-site monitoring system the system employs ultrasonic transducers to detect behavior in sows before, during and after parturition. An ultrasonic transmitting/receiving (T/R) circuit of 40 kHz was mounted above a conventional parturition bed. The T/R units use ultrasonic time-of-flight (TOF) ranging technology to measure the height of the confined sows at eight predetermined locations. From this data, three momentary postures of the sow are determined, characterized as standing-posture (SP), lateral-lying-posture (LLP) and sitting posture (STP). By examining the frequencies of position switch Stand-Up-Sequence (SUS) between standing-posture (SP), lateral-lying-posture (LLP) and sitting-posture (STP) rate can be determined for the duration of the sow' confinement. Three experimental pureblooded Landrace sows undergoing normal gestation were monitored for the duration of confinement. In agreement with common observation, the sows exhibited increased restlessness as parturition approached. Analysis of the data collected in our study showed a distinct peak in Stand-Up-Sequence (SUS, i.e. the transition from lying laterally to standing up ) and sitting-posture (STP) rate approximately 12 h prior to parturition, the observed peak being 5 to 10 times higher than observed on any other measurement day. It is concluded that the presented methodology is a robust, low-cost, lowlabor method for the continuous remote monitoring of sows and similar large animals for parturition and other behavior. It is suggested that the system could be applied to automatic prediction of sow parturition, with automatic notification of remote management personnel so human attendance at birth could reduce rates of sow and piglet mortality. The results of this study provide a good basis for enhancing automation and reducing costs in large-scale sow husbandry and have applications in the testing of various large mammals for the effects of medications, diets, genetic modifications and environmental factors.